Manufacture of motor fuel



Oct. 28, 1941. l l LE ROY G. STORY MANUFACTURE OF 'MOTOR FUEL- Filed lay 27, 1939 Patented Oct. 28, 1941 Le Roy G. Story,

The Texas Company,

ration of Delaware white Plains, N. Y., ossignor to' New York, N. Y., a. corpo- Applcaton May 27, 1939, Serial No. 276,149 4 Claims. (Cl. 1236-10) This invention relates to the manufacture of motor fuel and has to do particularly with the production of high antiknock gasoline hydrocarbons by the alkylation vof low boiling isoethane and the ethylene,

may be released from.

the accumulator through the gas release line I1. The liquid fraction comprising an unstable alkyl- Aation gasoine is passed from the accumulator through the line I8 and pump I9 to stabilizer paramos with olens, 20. A stabilized gasoline is separated ln the In accordance with the invention, paralin hystabilizer and withdrawn from the bottom theredrocarbons, suitably those containing between 2 of through line 22. A vapor fraction containing and 5 carbon atoms, are dehydrogenated to proall or a portion of the normal butano and lighter duce olens and the hot dehydrogenation prodhydrocarbons, is passed overhead from the staucts contacted with cool liquid products from an 10 bilizer' through the line 23 to a fractionator 24. alkylation process, thereby vaporizing the alkyla- In the fractionator 24 a parain fraction, comtion products to form a vapor fraction containt prisingl normal butane, is separated as a coning gasoline and normally gaseous hydrocarbons. densate and passed from the lower portion of the The vapor fraction is'separated into an alkylatefratohator through the line 25 by the Dump 26 and normally gaseous hydrocarbons, which are to the heating coil 3. A gaseous fraction rich in fractionated to produce a fraction rich in norolens is passed overhead from the fractionator mal butanes which is returned to the dehydrothrough the line 28 and condenser 29 and charged genation operation, and a fraction rich in olens through the line 30 by a pump 3| into the line which is charged to the alkylation operation. 32, ofr an alkylatien System.d In the line 3 2 a The invention will be more fully understood 2o mixture including catalyst and isbutane is cirfrom the following description read in connec- Culatod by the pump 33 through a lmixer 34, tion with the accompanying drawing which cooler 35 and reaction chamber 36. The reacshows one form of apparatus suitable for carrytien products from the reactor 36 are passed ing out the process of the invention. through a line 3l, any Portion 0r all being re- Referring to the drawing, a parain charging 25 circulated through the line 38 where it is picked stock, such as propane or butane, or a mixture up by the Pump 33- A portion of the Products thereof, is .charged through the line I to a heat- WithdreWrl from the reuCtOr 36 through the line ing coil 3 located in a heater 4. In the heating 3l und not recycled, is passed to a separator 40 coil'the hydrocarbons are raised to a tempera- Whereiu the Catalystrv Separates from the hydroture sufficiently high whereby substantial de- 30 Carbon andlmay be Withdrawn through the line hydrogonaton of the hydrocarbons takes place 4I and discharged from the system or recycled when contacted with a dehydrogenation catalyst. through the lirie 42- Fresh Catalyst tO'make up Such a temperature will usually range between for that discharged through the line 4l may be about 400 and 700 C. The hot products are', added through the line 43. Extraneous isotransferred from the coil 3 through the hne 5 to a4 35 butane may be introduced into the alkylation catalyst chamber 6 containing a dehydrogenation System through the line 49. The hydrocarbons catalyst, such as activated alumina, chromium Separated Out irl the Separator l are passed oxide or chromium Oxide on a1umna In passthrough the-l1ne t0 a neutralize): wherein ing through the catalyst chamber, the hot prodthe hydrocarbons are contacted with a neutraluots are intimately contacted with the catalyst 4o 12mg agent Such 'as dilute caustic Soda introand the hydrogen split therefrom. About 30 to duced through the line 4G and discharged of paraffins may be converted into olefins through the liuc 4T. The neutralized hydro when passing through the catalyst under the oorbohs are passed through the line 48. pump 50 above conditions. The dehydrogenation prodand une '0 t0 the Veperizer 3, referred t0 hereucts are transferred from the catalyst chamber 45 t0f 0re` 6 through the lino 1 to a vaporizer `a wherein -ln the alkylation operation, a suitable catalyst the hot dehydrogenation products are contacted Such'es aluminum Chloride, hydrated boron triwith ooo1 olkylatioh products 'introduced through iluorldo or sulfuric acid, may be used. sulfuric -the line |0 1n the Vaporizer the alkylato is acid of about 90 to 100% concentration is prefsubstantially vaporized and the hot dehydro- 50 ereble- The Catalyst is ntlmately. contacted genation products cooled. The products of With the-hLVdrOCerbOrlS in the liquid Phase at a higher boiling point than gasoline are sepatemperature of about Zero t0 100 F. and prefrated as a liquid fraction in the vaporizor erably about to 90F. Anexcess'of isobutane and may be withdrawn from the bottom thereof over thcl olofms is maintained in the charging through the lino |2, A vapor'ous fraction 0011-55 stock s and a higher ratio of isobutane to olens ymining gasoline and lighter hydrocarbons, is is Vmaintained in the reaction mixture. passed overhead from the vaporizer through If thecharge to the 'alkylation system convapor line I4 and condenser I5 to an accumulatorv taihS a Substantial emourit 0f C3 hydrocarbons. I6. Uncondensable or permanent gases, such as such as propane and propylene, it may be desirhydrogen, methane, and all or a portion of the o0 able to separate from theV hydrocarbons, discharged from the neutralizer 45, the propane.

For this purpose it is contemplated that a fractionator or other means of separating the propane may be installed in the line 48.

As an example' of the operation of the invention, normal butane is heated to a temperature of about 550 C. and contacted with a dehydrogenation catalyst comprising chromium oxide deposited on activated alumina. About 50% of the normal butane is converted into butylenes. The hot dehydrogenation products are passed to a vaporizer wherein they are intimately contacted with cool liquid products from a cooperating alkylation system. Substantially all the alkylate of gasoline boiling point and lighter is vaporized and a fraction higher boiling than gasoline is separated as a liquid. The vapors are cooled to form an unstable alkylate containing normally gaseous hydrocarbons, including the C4@ and a I portion of the C3 hydrocarbons. The lighter hydrocarbons including hydrogen, methane, C2 hydrocarbons and a portion of the C3 hydrocarbons, are discharged from the system. The unstabilized alkylate is subjected to stabilization to separate overhead substantially all the normally gaseous hydrocarbons. A stabilized alkylate of gasoline boiling range is withdrawn from the system. The normally gaseous hydrocarbons `separate overhead from the stabilizer are fractionated to separate normal butane which is returned to the dehydrogenation operation. 'I'he remaining gases predominating in butylene and isobutane are charged along with additional extraneous isobutane if necessary-to produce an excess'of isobutane over olens, to an alkylation operation wherein the isobutane is alkylated by the olefns in the presence of sulfuric acid of about 98% concentration at a temperature of about 60 F. The alkylation products are separated from the catalyst, neutralized and charged to the vapor-L izer to which the hot products from the dehy` drogenation operation are introduced. A gasoline alkylate is recovered from the system, having an octane number of about 9|).-

The present invention has the advantage of utilizing the heat from the dehydrogenation operation for redistilling the alkylate. The alkylate also scrubs and removes any tarry materials from the hot dehydrogenation products. A further advantage of the invention is the elimination of fractionation of thealkylate and dehydrogenation products which are expensive operations when the processes are conducted separate.

Obviously many modifications and variations of the invention as hereinbefore set forth, may be made without departing from the spirit and scope thereof. and therefore only such limitations should be imposed as are indicated in pended claims.

I claim:

1. A process for the manufacture of high antiknock gasoline hydrocarbons, which comprises dehydrogenating normally gaseous hydrocarbons the appredominatlng in parafiins containing between 2 and 5 carbon atoms to form a hot mixture of parains and olelns. contacting said hot mixture with liquid products from, an alkylation operation, thereby vaporizing said liquids to form a vaporous and gaseous mixture of dehydrogenation and alkylation products, fractionating said vaporous mixture to form an alkylate and a norpmally gaseous hydrocarbon fraction containing olens and parafiins, fractionating said gaseous traction toproduce a fraction rich in olens and a fraction rich in pai-amas. charging said olen-rich fraction to the alkylation operation wherein said olens are alkylated with isobutane in the presence of an alkylation catalyst and returning said paraihn-rich fraction to the dehydrogenation operation.

2.A process for the manufacture of high antiknock gasoline hydrocarbons, which comprises vdehydrogenating normally gaseous hydrocarbons predominating in paraihns containing between 2 and 5 carbon atoms to form a hot mixture of parailns and oleiins, contacting said hot mixture jecting said olefin-rich fraction to an alkylation A operation in the presence of excess isobutane and an alkylation catalyst whereby the isobutane is alkylated by the olens, separating the alkylation products from the catalyst and passing said products to the operation in which the alkylation' products are contacted with hot products of dehydrogenation.

3. A process for the manufacture of high antiknock gasoline hydrocarbons, which comprises dehydrogenating n-butane to butylene, contacting the hot dehydrogenation products with cool products from an alkylation operation, thereby vaporizing the alkylation products to form a vaporous fraction, separating from said fraction an unstabilized alkylate containing gasoline, normal butane and butylenes, stabilizing said alkylate to produce a stable alkylate and a stabilizer overhead containing said normal butane and butylenes, fractionating the stabilizer overhead Y to form a fraction rich in butylenes'and a-fraction rich in normal butane, returning said n-butane fractionto the dehydrogenation operation, charging said butylene fraction to an alkylation operation wherein isobutane is alkylated by the butylenes in the presence of an alkylation catalyst, recovering from the alkylation operation an alkylate and passing said alkylate to the operation in which the hot dehydrogenation products are contacted with ucts'.

knock gasoline hydrocarbons, which comprises subjecting low boiling parain hydrocarbons to dehydrogenation, thereby forming a hot mixture of dehydrogenation products, contacting said hot dehydrogenation products with cooler products from an alkylation operation thereby forming a. vapor mixture, separating from said mixture a normally liquid fraction, also separating from v said mixture a light fraction containing normally gaseous olens, subjecting said light fraction to an alkylation operation in the presence of an alkylation catalyst and low boiling isoparaftlns in excess of the oleiins, separating a hydrocarbon fraction containing alkylate from the reaction products and passing said hydrocarbon fraction to the'operation in which the products of the alkylation operation are contacted with the hot dehydrogenation products.

' La nor o. STORY.

cool alkylation prod- 4. A process for the manufacture of high anti- 

